1,721,025 research outputs found
Solar spectral reflectance of building envelope materials after natural exposure in Rome and Milano, and after accelerated aging
No full textMaterial weathering, dirt deposition (mainly soot and organic matter) and microbial growth, collectively referred to as aging, modify the optical and radiative response of building envelopes. Long-term data about the initial and aged solar reflectance are available for roofing products exposed at three sites in the U.S. (Arizona, Florida, and Ohio). Based on this dataset, an accelerated weathering and soiling protocol was developed by the Lawrence Berkeley National Laboratory (LBNL) to mimic the spectral reflectance after three years of natural exposure.
Herein, we present an extension of the accelerated aging protocol to reproduce in the laboratory the conditions in Italian urban areas (and, in general, in urban areas), by tuning the spraying duration and soiling composition.
We compared the UV-Vis-NIR reflectance of naturally-aged samples (18 months in Rome and Milano) with that of samples exposed to accelerated weathering and soiling in the laboratory, achieving a good agreement between the spectral reflectance of the naturally-aged samples and of those aged with the accelerated protocol. The results herein presented relate to single-ply roofing membranes, terracotta tiles, and façades finishing coats. For very reflective membranes (initial solar reflectance greater than 0.80), after the first 18 months of natural exposure, we observe absolute losses of solar reflectance in average equal to 0.20 (maximum of 0.25), and the accelerated exposure is able to reproduce the UV-Vis-NIR spectra to within 0.02 for most of tested products
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparative analysis of different methods to evaluate the thermal conductivity of homogenous materials
No full textThermal conductivity of materials for structural elements and thermal insulation represents a fundamental parameter in the assessment of the energy need of buildings. In this paper, two different systems for thermal conductivity measurement are compared, based respectively on the calibrated hot box and on the guarded hot plate methods. The study is specifically aimed at assessing the range of thermal transmittance where the hot box system is suitable and verifying the strengths and the weaknesses of the system.
The comparison between measurements on specimens with different thermal conductivity and thickness showed that the two methods are substantially equivalent in the considered range of thermal conductivity, but are not completely interchangeable. In particular, the measurement campaign confirmed the expectation that the hot box system gives more accurate results with low thermal resistance samples
L'influenza della diversa temperatura ambientale di allevamento sulla produzione della carne del capretto di razza Garganica.
No full textComparative analysis of different methods to evaluate the thermal conductivity of homogenous materials
No full textThermal conductivity of materials for structural elements and thermal insulation represents a fundamental parameter in the assessment of the energy need of buildings. In this paper, two different systems for thermal conductivity measurement are compared, based respectively on the calibrated hot box and on the guarded hot plate methods. The study is specifically aimed at assessing the range of thermal transmittance where the hot box system is suitable and verifying the strengths and the weaknesses of the system.
The comparison between measurements on specimens with different thermal conductivity and thickness showed that the two methods are substantially equivalent in the considered range of thermal conductivity, but are not completely interchangeable. In particular, the measurement campaign confirmed the expectation that the hot box system gives more accurate results with low thermal resistance samples
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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